133 research outputs found

    miR-1246 in tumor extracellular vesicles promotes metastasis via increased tumor cell adhesion and endothelial cell barrier destruction

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    BackgroundTumor blood vessels play a key role in tumor metastasis. We have previously reported that tumor endothelial cells (TECs) exhibit abnormalities compared to normal endothelial cells. However, it is unclear how TECs acquire these abnormalities. Tumor cells secrete extracellular vesicles (EVs) to create a suitable environment for themselves. We have previously identified miR-1246 to be more abundant in high metastatic melanoma EVs than in low metastatic melanoma EVs. In the current study, we focused on miR-1246 as primarily responsible for acquiring abnormalities in TECs and examined whether the alteration of endothelial cell (EC) character by miR-1246 promotes cancer metastasis.MethodsWe analyzed the effect of miR-1246 in metastatic melanoma, A375SM-EVs, in vivo metastasis. The role of tumor EV-miR-1246 in the adhesion between ECs and tumor cells and the EC barrier was addressed. Changes in the expression of adhesion molecule and endothelial permeability were examined.ResultsIntravenous administration of A375SM-EVs induced tumor cell colonization in the lung resulting in lung metastasis. In contrast, miR-1246 knockdown in A375SM decreased lung metastasis in vivo. miR-1246 transfection in ECs increased the expression of adhesion molecule ICAM-1 via activation of STAT3, followed by increased tumor cell adhesion to ECs. Furthermore, the expression of VE-Cadherin was downregulated in miR-1246 overexpressed EC. A375SM-EV treatment enhanced endothelial permeability. VE-Cadherin was validated as the potential target gene of miR-1246 via the target gene prediction database and 3′ UTR assay.ConclusionmiR-1246 in high metastatic tumor EVs promotes lung metastasis by inducing the adhesion of tumor cells to ECs and destroying the EC barrier

    Recovery from Unrecognized Sleep Loss Accumulated in Daily Life Improved Mood Regulation via Prefrontal Suppression of Amygdala Activity

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    Many modern people suffer from sleep debt that has accumulated in everyday life but is not subjectively noticed [potential sleep debt (PSD)]. Our hypothesis for this study was that resolution of PSD through sleep extension optimizes mood regulation by altering the functional connectivity between the amygdala and prefrontal cortex. Fifteen healthy male participants underwent an experiment consisting of a baseline (BL) evaluation followed by two successive interventions, namely, a 9-day sleep extension followed by one night of total sleep deprivation (TSD). Tests performed before and after the interventions included a questionnaire on negative mood and neuroimaging with arterial spin labeling MRI for evaluating regional cerebral blood flow (rCBF) and functional connectivity. Negative mood and amygdala rCBF were significantly reduced after sleep extension compared with BL. The amygdala had a significant negative functional connectivity with the medial prefrontal cortex (FCamg–MPFC), and this negative connectivity was greater after sleep extension than at BL. After TSD, these indices reverted to the same level as at BL. An additional path analysis with structural equation modeling showed that the FCamg–MPFC significantly explained the amygdala rCBF and that the amygdala rCBF significantly explained the negative mood. These findings suggest that the use of our sleep extension protocol normalized amygdala activity via negative amygdala–MPFC functional connectivity. The resolution of unnoticed PSD may improve mood by enhancing frontal suppression of hyperactivity in the amygdala caused by PSD accumulating in everyday life

    Tumor-Derived Microvesicles Induce Proangiogenic Phenotype in Endothelial Cells via Endocytosis

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    Background: Increasing evidence indicates that tumor endothelial cells (TEC) differ from normal endothelial cells (NEC). Our previous reports also showed that TEC were different from NEC. For example, TEC have chromosomal abnormality and proangiogenic properties such as high motility and proliferative activity. However, the mechanism by which TEC acquire a specific character remains unclear. To investigate this mechanism, we focused on tumor-derived microvesicles (TMV). Recent studies have shown that TMV contain numerous types of bioactive molecules and affect normal stromal cells in the tumor microenvironment. However, most of the functional mechanisms of TMV remain unclear. Methodology/Principal Findings: Here we showed that TMV isolated from tumor cells were taken up by NEC through endocytosis. In addition, we found that TMV promoted random motility and tube formation through the activation of the phosphoinositide 3-kinase/Akt pathway in NEC. Moreover, the effects induced by TMV were inhibited by the endocytosis inhibitor dynasore. Our results indicate that TMV could confer proangiogenic properties to NEC partly via endocytosis. Conclusion: We for the first time showed that endocytosis of TMV contributes to tumor angiogenesis. These findings offer new insights into cancer therapies and the crosstalk between tumor and endothelial cells mediated by TMV in the tumor microenvironment

    Japanese intelligence and imperial diplomacy in 1920s China

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    This study examines three cases, the First Zhili-Fengtian War of 1922, Second Zhili-Fengtian War of 1924, and Guo Songling Revolt of 1925 from an intelligence perspective to see them as something more than a simple path to the 1931 Manchurian Incident. Past scholarship has highlighted institutional rivalry over China policy between the Japanese Foreign and War Ministries, and a consequent mismatch between words and deeds in Japanese diplomacy. This study argues that Japanese civilian and military rivalries have been overplayed and that the so-called dual diplomacy of contrasting words and deeds was painstakingly learned as requisite for great power status. From a larger perspective, the case studies demonstrate that intelligence activities had become a common tool for great powers in interwar China and that Japanese intelligence became quite successful in this competitive environment

    Japanese intelligence and imperial diplomacy in 1920s China

    No full text
    This study examines three cases, the First Zhili-Fengtian War of 1922, Second Zhili-Fengtian War of 1924, and Guo Songling Revolt of 1925 from an intelligence perspective to see them as something more than a simple path to the 1931 Manchurian Incident. Past scholarship has highlighted institutional rivalry over China policy between the Japanese Foreign and War Ministries, and a consequent mismatch between words and deeds in Japanese diplomacy. This study argues that Japanese civilian and military rivalries have been overplayed and that the so-called dual diplomacy of contrasting words and deeds was painstakingly learned as requisite for great power status. From a larger perspective, the case studies demonstrate that intelligence activities had become a common tool for great powers in interwar China and that Japanese intelligence became quite successful in this competitive environment

    Synergistic Enhancement of Cellular Uptake With CD44-Expressing Malignant Pleural Mesothelioma by Combining Cationic Liposome and Hyaluronic Acid-Lipid Conjugate

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    Malignant pleural mesothelioma (MPM) is a highly aggressive form of cancer, with a median survival of less than 1 year. It is well known that the hyaluronan (HA) receptor CD44 is highly expressed by MPM cells and is reported to be correlated with a poor prognosis. We herein report on the development of a new type if drug delivery system against CD44 that involves the use of lipid nanoparticles (LNPs) equipped with a new type of HA derivative. In this study, we evaluated HA-lipid conjugation (HAL) via the end of the HA molecule through reductive amination, a process that allowed the carboxylate group to remain intact. As a result, the HAL-modified LNP appears to be a potent nanoparticle for dealing with MPM. Surprisingly, the use of a combination of a cationic lipid and HAL had a synergistic effect on cellular uptake in MPM and consequently permitted an anti-cancer drug such as cis-diamminedichloro-platinum(II) (CDDP). Intrapleural injection of CDDP-loaded HAL-LNP (1.5 mg/kg as CDDP) per week significantly suppressed the progression of this type of cancer in an MPM orthotopic model. These results suggest that HAL-modified LNP represents a potent delivery system for MPM cells that express high levels of CD44. (c) 2019 American Pharmacists Association (R). Published by Elsevier Inc. All rights reserved

    Significance of anti-angiogenic therapy in head and neck cancer—Heterogeneity of tumor endothelium

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    Tumor angiogenesis is necessary for solid tumor progression and metastasis. Thus, targeting tumor blood vessels is an important strategy for cancer therapy. Especially, it would give large benefit to head and neck cancer patients if ideal anti-angiogenic drug is developed. Tumor blood vessels have been shown to differ from their normal counterparts, for example, by changes in morphology. An important concept in tumor angiogenesis is that tumor endothelial cells are assumed to be genetically normal, even though these endothelial cells are structurally and functionally abnormal. To date, many anti-angiogenic drugs have been developed, but it has been also reported to cause toxic side effects. To develop ideal anti-angiogenic therapies, understanding tumor endothelial cell abnormalities is important. We have isolated tumor endothelial cells from mouse tumor xenografts and have shown that tumor endothelial cells are abnormal. Tumor endothelial cells upregulate many genes, such as epidermal growth factor receptor. Tumor endothelial cells are also more sensitive to EGF. Unexpectedly, tumor endothelial cells were cytogenetically abnormal. In marked contrast, freshly isolated normal endothelial cells were diploid. We conclude that tumor endothelial cells can acquire cytogenetic abnormalities while in the tumor microenvironment. Here, we provide an overview of the current studies on tumor endothelial cell abnormalities

    Contribution of Tumor Endothelial Cells in Cancer Progression

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    Tumor progression depends on the process of angiogenesis, which is the formation of new blood vessels. These newly formed blood vessels supply oxygen and nutrients to the tumor, supporting its progression and providing a gateway for tumor metastasis. Tumor angiogenesis is regulated by the balance between angiogenic activators and inhibitors within the tumor microenvironment. Because the newly formed tumor blood vessels originate from preexisting normal vessels, tumor blood vessels, and tumor endothelial cells (TECs) have historically been considered to be the same as normal blood vessels and endothelial cells; however, evidence of TECs’ distinctive abnormal phenotypes has increased. In addition, it has been revealed that TECs constitute a heterogeneous population. Thus, TECs that line tumor blood vessels are important targets in cancer therapy. We have previously reported that TECs induce cancer metastasis. In this review, we describe recent studies on TEC abnormalities related to cancer progression to provide insight into new anticancer therapies
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